NASA’s LRO Captures Rare Image Of Unusual Spacecraft Moving At 11,500 KM/H In Lunar Orbit

NASA’s Lunar Reconnaissance Orbiter (LRO) recently captured an exciting moment in space as it took pictures of South Korea’s Danuri lunar orbiter while both spacecraft were orbiting the Moon. This unique event happened between March 5 and 6, 2024, when LRO and Danuri were in nearly parallel paths but moving in opposite directions.

The images, released by NASA’s Goddard Space Flight Center in collaboration with Arizona State University, demonstrate the incredible precision and timing required for such a challenging photographic opportunity. The two spacecraft were traveling at an impressive speed of 11,500 kilometers per hour (7,200 miles per hour), so LRO had only a very brief moment to aim its camera and catch Danuri in its view.

LRO has been continuously orbiting the Moon since June 18, 2009, flying at about 80 kilometers (50 miles) above the lunar surface, while Danuri was positioned at 8 kilometers (5 miles) below it. The quick movement meant that even with an ultra-short exposure time of just 0.338 milliseconds, Danuri appeared stretched in the images, looking almost ten times its actual size due to the high speed of both spacecraft.

The images were taken using the Lunar Reconnaissance Orbiter Camera (LROC), developed by Arizona State University. Mark Robinson, who is the lead investigator for the LROC, explained that the extremely high speed of the two spacecraft required very careful timing to ensure they could capture this fleeting moment. NASA’s Goddard Space Flight Center manages the LRO mission as part of its Science Mission Directorate based in Washington, D.C.

Danuri, also known as the Korea Pathfinder Lunar Orbiter (KPLO), marks South Korea’s first mission to explore the Moon. It was developed by the Korea Aerospace Research Institute (KARI) and successfully entered lunar orbit in December 2022, after a four-month journey from Earth. The main goal of the Danuri mission is to create maps of the Moon’s surface and search for potential deposits of water ice in shadows on the lunar poles.

Danuri is equipped with an advanced NASA-created tool named ShadowCam, which is 200 times more sensitive than LRO’s narrow-angle camera. In April 2023, Danuri used its ShadowCam to capture images of LRO from a distance of 18 kilometers (11 miles).

Capturing images of fast-moving spacecraft like LRO and Danuri is a very complex job, and the successful photos taken during this encounter show the meticulous planning of NASA engineers. In one of LRO’s imaging attempts, the camera was tilted 43 degrees downward from its usual position to line up with Danuri’s path. The way these spacecraft are organized further complicates the imaging process, as even small adjustments can significantly impact the final images. NASA noted that despite all efforts, the final pictures displayed noticeable motion blur, which is common when photographing moving objects in space.

The successful imaging encounter also highlights the increasing number of international missions to the Moon, with countries like the United States, South Korea, India, China, Japan, and private companies now heavily investing in lunar exploration. NASA’s Artemis program aims to bring humans back to the Moon in the coming years, relying on detailed lunar maps provided by missions such as LRO and Danuri. South Korea also has plans to deploy a lunar lander by the early 2030s.

What once seemed like a rare event—the encounter of two lunar missions—is likely to become more common as the number of robotic missions and crewed missions exploring the Moon increases.